TWI812890B - Non-telecentric light guide elements - Google Patents

Abstract

The present disclosure relates to systems and methods relating to the fabrication of light guide elements. An example system includes an optical component configured to direct light emitted by a light source to illuminate a photoresist material at one or more desired angles so as to expose an angled structure in the photoresist material. The photoresist material overlays at least a portion of a first surface of a substrate. The optical component includes a container containing a light-coupling material that is selected based in part on the one or more desired angles. The system also includes a reflective surface arranged to reflect at least a first portion of the emitted light to illuminate the photoresist material at the one or more desired angles.

Description

Non-telecentric light guide element

The present invention relates to systems and manufacturing methods related to light guide elements and, more particularly, to non-telecentric light guide elements.

Light guide devices may include optical fibers, waveguides, and other optical elements (eg, lenses, mirrors, mirrors, etc.). These light guide devices can transmit light from an input surface to an output surface through total internal reflection or partial internal reflection. Additionally, light guides may include active and passive optical components, such as optical switches, combiners, and splitters.

Optical systems can utilize light guides for a variety of purposes. For example, optical fibers can be implemented to transmit optical signals from a light source to a desired location. In the case of a light detection and ranging (LIDAR) device, a plurality of light sources can emit light, which can be optically coupled to a light guide in order to be directed into a given environment. Light emitted into the environment can be detected by a receiver of the LIDAR device to provide estimated distances to objects in the environment.

The present invention relates to systems and methods of fabrication related to light guide elements configured to be mounted in an optical system in a non-telecentric configuration. Additionally or alternatively, the systems and methods described herein may be adapted for use in the fabrication of optical systems. For example, this disclosure describes certain optical components (eg, light guides) and methods of making them. Optical waveguides may include one or more structures, such as mirror surfaces, vertical structures, and/or tilted structures.

In a first aspect, a system is provided. The system includes an optical component configured to direct light emitted by a light source to illuminate a photoresist material at one or more desired angles to expose a tilted structure in the photoresist material. The photoresist material covers at least a portion of a first surface of a substrate. The optical assembly includes a container containing a light coupling material selected based at least in part on the one or more desired angles. The system also includes a reflective surface configured to reflect at least a first portion of the emitted light to illuminate the photoresist material at the one or more desired angles.

In a second aspect, an optical system is provided. The optical system includes a substrate and a light emitter device. The optical system also includes an optical waveguide disposed along a surface of the substrate. The optical waveguide contains a mirror section. The optical waveguide is configured to guide light emitted by the light emitter device. A portion of the directed light interacts with the mirror portion to direct reflected light into an environment of the optical system. The mirror portion includes a reflective surface configured between 30 degrees and 60 degrees relative to the substrate.

In a third aspect, a method is provided. The method includes placing a substrate near one end of an optical component. The photoresist material covers at least a portion of a first surface of the substrate. The optical component includes: (i) a container containing an optical coupling material; and (ii) a reflective surface. The method may also include causing a light source to emit light into the optical component. The reflective surface reflects at least a first portion of the emitted light to illuminate the photoresist material at one or more desired angles, thereby exposing at least a portion of a tilted structure in the photoresist material.

Other aspects, embodiments, and implementations will become apparent to those of ordinary skill by reading the following detailed description, as appropriate, with reference to the accompanying drawings.

Exemplary methods, devices, and systems are described herein. It should be understood that the words "example" and "illustrative" are used herein to mean "serving as an example, instance, or illustration." Any embodiment or feature described herein as an "example" or "illustrative" is not necessarily to be construed as being preferred or advantageous over other embodiments or features. Other embodiments may be utilized, and other changes may be made, without departing from the scope of the subject matter presented herein.

Accordingly, the illustrative embodiments described herein are not intended to be limiting. Aspects of the invention as generally described herein and illustrated in the Figures may be configured, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are contemplated herein.

Furthermore, the features depicted in each figure may be used in combination with each other unless background content suggests otherwise. Therefore, the drawings should generally be considered as schematics of one or more overall embodiments, with the understanding that not all illustrated features may be required of each embodiment. I. Overview

The light guide may include optical elements that may be configured to guide light within the light guide. These optical elements may include structures that reflect light (fully or partially) to transmit light from an input face to an output face of the light guide. For example, optical elements can be vertical and/or tilted structures that can direct light. More specifically, a vertical structure can direct light along a length of the structure. A tilted structure can be coated with a metal (which is optically reflective), thereby effectively acting as a mirror that reflects incident light in a specific direction.

In an exemplary embodiment, the light guide may be formed from a photoresist material and may be configured to guide infrared light.

In practice, light guides can be fabricated using photolithography, which uses a light source to expose the structure of the optical element in a photoresist material overlaying a substrate. The desired structure can be exposed by exposure light illuminating the photoresist having a mask pattern. In these cases, the vertical structures are exposed by exposure light incident normally on the photoresist material to expose the photoresist at a normal angle.

On the other hand, the tilted structure is exposed by exposure light incident on the photoresist material at an illegal angle. For example, to expose a tilted structure, an angle of refraction of light in the photoresist material is set to a desired angle of the tilted structure. However, achieving certain refraction angles in photoresist materials can be challenging. For example, when one of the media between the light source and the photoresist material is air, the refraction angle in the photoresist material for exposing some tilted structures may not be achieved according to Snell's law.

One current solution is to use immersion photolithography to achieve the desired refraction angle in the photoresist material. In this solution, the substrate can be immersed in a medium with a moderate refractive index. According to Snell's law, the material is selected to have a refractive index high enough to transmit refracted light at designed angles into the photoresist material. To expose tilted structures in wetted photoresist material, a robotic device moves a light source at a specific angle relative to the photoresist material to expose the photoresist material at the desired angle. While this solution can be used to fabricate tilted structures, it is inefficient and time-consuming. In practice, manufacturing optical components using this technology can take several hours.

Immersion lithography systems and methods are disclosed herein, which may include a photoresist material configured to direct light from a light source to illuminate a photoresist material on a substrate at a plurality of desired angles and thereby cause the photoresist material to Exposure of structures from various angles. The optical assembly may include a container holding an index matching material (eg, water or another fluid) selected based at least in part on the desired angle. The optical component may also include a reflective surface configured to reflect at least a portion of the light to illuminate the photoresist material at a desired angle.

In an exemplary embodiment, the reflective surface includes a plurality of different angles that create a plurality of desired angles in the photoresist material. In such cases, the tilted structure can be formed with different controllable angles based on a shape determination of the reflective surface.

In some embodiments, the tilted structure may be coated with a reflective material to form a tilted mirror structure. The tilted mirror structure can be optically coupled to a respective plurality of light guides (eg, optical waveguides). A plurality of light emitter devices may be configured to emit respective light pulses along the light guide. Light pulses can be guided along the light guide and reflected out of the plane by tilted mirror structures. In these cases, light pulses can be emitted into an environment at different angles.

A LIDAR system may include a plurality of light emitter devices and a light guide manifold. The light guide manifold may include a plurality of waveguides corresponding to and optically coupled to respective light emitter devices. A plurality of light emitter devices may be configured to emit light pulses along respective waveguides. The light guide manifold may also include a plurality of tilted mirror structures optically coupled to the waveguide. In an exemplary embodiment, a plurality of tilted mirror structures may be configured to direct light pulses away from the plane of the waveguide and toward an environment of the LIDAR. Additionally, the respective angles of the tilted mirror structures can be different, allowing controllably directing light pulses toward the environment along different emission angles. For example, tilted mirror structures may be configured at 42 degrees, 45 degrees, and 48 degrees relative to the plane of the waveguide. However, other angles and/or angle ranges are contemplated and possible. II. Illustrative system

As discussed above, fabricating some desired structures can be challenging using current photolithography systems. For example, when the medium between the light source and the photoresist material is air, it may not be feasible to create some tilted structures. Specifically, according to Snell's law, when the medium between the light source and the photoresist material is air, the refraction angle in the photoresist material for exposing the tilted structure may not be achieved.

Methods and systems for fabricating optical components, such as optical waveguides, are disclosed herein. In particular, methods and systems can be used to fabricate optical elements that include desired structures (eg, desired tilted and/or vertical structures). In addition, the methods and systems disclosed herein can fabricate optical components more quickly and efficiently than manufacturing systems currently used in practice.

Figure 1 illustrates a system 100 according to an exemplary embodiment. System 100 can be a photolithography system that can be configured to fabricate optical elements by exposing desired structures in a photopatternable material. Additionally, system 100 may be utilized in the context of optical immersion lithography. In such cases, system 100 can be used to form tilted structures at desired angles in a photoresist material.

System 100 includes an optical assembly 110 configured to direct light 12 emitted by a light source 10 to illuminate a photoresist material 130 at one or more desired angles to tilt one of the photoresist materials 130 Structure 134 exposed. As explained herein, optical assembly 110 may be configured to manipulate light emitted by light source 10 to expose desired structures in photoresist material 130 .

In these embodiments, the photoresist material 130 covers at least a portion of a first surface 142 of a substrate 140 . For example, photoresist material 130 may include SU-8 polymer, Kloe K-CL negative photoresist, Dow PHOTOPOSIT negative photoresist, or JSR negative tint THB photoresist. It will be understood that photoresist material 130 may include other polymeric photopatternable materials.

Substrate 140 may be a transparent substrate such as glass and/or another material that is substantially transparent to a desired wavelength range (eg, near-infrared wavelengths or another infrared wavelength range).

In some embodiments, light source 10 may be configured to emit light at one or more wavelengths. For example, light source 10 may be configured to emit visible light and/or ultraviolet (UV) light. Additionally, light source 10 may include one or more components (eg, a lens and/or a collimator) that enable light source 10 to emit collimated or substantially collimated light. For example, light can be collimated using anisotropic collimation. In such cases, light source 10 may be an anisotropically collimated light source.

In some embodiments, light source 10 may emit p-polarized light to reduce reflections from the substrate-photoresist interface and from a backside of substrate 140 . Accordingly, light source 10 may include a polarizer (eg, a polarizing filter) that enables light source 10 to emit p-polarized light. Additionally and/or alternatively, light source 10 may include an integrated timer that may allow system 100 to control an exposure time. In an exemplary embodiment, light source 10 may be a 500 watt UV light source. In another exemplary embodiment, light source 10 may be a 500 watt collimated UV light source.

Additionally or alternatively, the light source 10 may be a mercury or xenon discharge lamp. In other embodiments, the light source 10 may be a deep ultraviolet (UV) excimer laser, such as a 193 nm ArF excimer laser. However, other light sources suitable for optical lithography and/or immersion lithography are possible and considered.

In one embodiment, optical assembly 110 may be configured to manipulate emitted light to expose photoresist material 130 . To manipulate the emitted light, optical assembly 110 may be positioned proximate to and optically coupled to light source 10 . In one embodiment, the optical component 110 may be positioned above or below the light source 10 relative to a horizontal plane. Other orientations of optical assembly 110 and light source 10 are contemplated and possible.

Optical assembly 110 includes a container 112 containing a light coupling material 114 selected at least in part based on one or more desired angles. In an exemplary embodiment, optical coupling material 114 may include a liquid medium (eg, purified water) having a refractive index greater than 1. In other examples, the optical coupling material 114 may be ethylene glycol (refractive index ~ 1.43) and/or glycerol (refractive index ~ 1.47), as well as other examples. In one example, light coupling material 114 may be any material with a refractive index suitable for supporting the transmission of light rays that, after refraction, have a desired angle in the photoresist. Additionally or alternatively, the light coupling material 114 may be a solid (eg, clear acrylic and cured silicone or epoxy), liquid, adhesive, or gel that fills at least a portion of an interior of the container 112 . However, other types of light coupling materials common to immersion lithography are possible and considered herein.

In some embodiments, container 112 may be made from one or more materials, such as aluminum and/or other types of metals. A portion of a surface of container 112 may be transparent so that light emitted by light source 10 may enter container 112 . A portion of the other surface of container 112 may also be transparent to allow light to exit container 112 to expose photoresist material 130. For example, portions of a top surface and a bottom surface of container 112 may be transparent to allow light to enter/leave container 112 . Obviously, the transparent portion can be transparent to this type of emitted light. For example, when the emitted light is UV light, the transparent portion may be transparent to UV light. Exemplary materials for the transparent portion may include glass and/or any other material that is transparent to light emitted by light source 10 .

Optical assembly 110 additionally includes at least a first portion 14 configured to reflect light to illuminate a reflective surface 116 of photoresist material 130 at one or more desired angles. In an exemplary embodiment, reflective surface 116 may include a surface mirror, a concave lens, a convex lens, a lens, and/or a diffraction mirror. In some embodiments, optical component 110 may include a plurality of reflective surfaces 116 . In such cases, reflective surface 116 may include mirrors of the same type, orientation, and/or characteristics.

In some embodiments, the one or more desired angles may include at least one of: 42 degrees, 45 degrees, and 48 degrees relative to first surface 142 . In this manner, the photoresist material 130 may be exposed using UV light and developed to form a plurality of tilted structures 134 . However, it should be understood that the sloped structure 134 may have surfaces with other angles relative to the first surface 142 . For example, the one or more desired angles may include at least one angle relative to first surface 142 selected from an angle range between 40 degrees and 60 degrees.

In some embodiments, reflective surface 116 may include a plurality of planar mirror portions 118 corresponding to one or more desired angles.

Additionally or alternatively, reflective surface 116 may include one or more curved mirror portions 119 .

In some embodiments, system 100 may further include an aperture mask 160 positioned between light source 10 and substrate 140 . Aperture mask 160 includes one or more openings 162, each opening corresponding to a respective desired structure in photoresist material 130 (eg, vertical structure 132 and/or angled structure 134). At least a portion of the emitted light transmitted through each opening exposes the respective desired structure to which the opening corresponds. As an example, each desired structure may include at least one vertical structure 132 and at least one inclined structure 134 .

In one embodiment, each opening 162 of aperture mask 160 may correspond to a respective desired feature in photoresist material 130 for exposure. Aperture mask 160 may be used to define approximate fields for different exposure light angles by selectively allowing light to travel through the mask's openings. Each opening may allow a respective portion of light to travel therethrough, which may then be used (directly or indirectly) to expose a particular feature in photoresist material 130 .

For example, aperture mask 160 includes a first opening. In these cases, the first opening is configured to allow a first portion of the emitted light to interact with a first portion of the reflective surface 116 . The first portion of reflective surface 116 is configured to redirect the first portion of emitted light 14 to expose at least one tilted structure 134 .

In some embodiments, aperture mask 160 includes a second opening. In such cases, the second opening is configured to allow a second portion 16 of the emitted light to expose at least one vertical structure 132 .

In various embodiments, the aperture mask 160 may include one or more of the intensities of light incident on normal field regions and oblique field regions configured to reflect and/or absorb light in order to balance the light intensity incident on the photoresist material 130 Density filter. One such neutral density filter may include incorporating a pattern of small opaque and/or transparent circles onto a background (eg, a pattern of dots) opposite the aperture mask 160. In this case, light transmitted through such a neutral density filter can be uniformly attenuated as it interacts with the photoresist material 130 . Additionally, light can be slightly blurred due to diffraction. Light input to the system is not perfectly collimated and can have an angular range of 1 to 2 degrees. Therefore, the dot pattern can be blurred to a uniform intensity at a sufficient "throw" distance (approximately the tangent of the dot period divided by the angular range). In some embodiments, blurring can occur across substantially the entire width of the optics frame (eg, 50 mm) for a fine pattern at 1 mm periodicity. Therefore, light transmitted through the neutral density filter region may be substantially blurred to create a uniform illumination intensity at the photoresist material 130 .

In the exemplary embodiment, at least a portion of a first surface and at least a portion of a second surface of container 112 are transparent. In these cases, the emitted light 12 enters the container 112 through the transparent portion of the first surface, and wherein the emitted light illuminates the photoresist material 130 through the transparent portion of the second surface.

In various embodiments, system 100 may include a reticle 170 . In some embodiments, photomask 170 is disposed proximate photoresist material 130 . Photomask 170 is configured to define individual desired structures in photoresist material 130 .

In various embodiments, photomask 170 may be positioned adjacent substrate 140 , possibly over photoresist material 130 . In one embodiment, photomask 170 may be used to define individual structures in photoresist material 130 . In particular, reticle 170 may include a pattern or transparency that allows exposure light to be transmitted through openings into photoresist material 130 . In one embodiment, the pattern may correspond to the desired configuration of one of the optical waveguides or other structures formed from the photoresist material 130 . That is, the photomask 170 may include openings corresponding to the vertical structures 132 and/or the tilted structures 134 . When substrate 140 is exposed to light, light transmitted through an opening corresponding to a vertical structure creates a vertical structure in photoresist material 130, and light transmitted through an opening corresponding to a tilted structure A tilted structure 134 may be created in the photoresist material 130 (after the photoresist bake and/or development process). As explained herein, light reflected from reflective surface 116 may be transmitted through openings of photomask 170 corresponding to tilted structures 134 .

In some embodiments, optical assembly 110 further includes a device configured to remove stray light within optical assembly 110 . For example, optical component 110 may include a light baffle or another type of optical noise mitigating structure and/or material.

In various examples, an optical absorber may be disposed behind substrate 140 (eg, along a surface opposite photoresist material 130). The optical absorber may be configured to prevent backscattered light from causing artifacts in the photoresist material 130 . The optical absorber may include a coating on the backside of substrate 140 . Alternatively, the optical absorber may be a dark or opaque material separate from substrate 140 . For example, an optical coupling material (eg, optical coupling material 114) may be disposed between the backside of substrate 140 and the optical absorber.

In some embodiments, substrate 140 may be wetted into light coupling material 114 such that photoresist material 130 faces a second surface of container 112 . At least a portion of the second surface of container 112 is transparent. In this case, the emitted light 12 from the light source 10 enters the container 112 through the transparent portion of the second surface of the container 112 .

Figure 2A illustrates a system 200 according to an exemplary embodiment. System 200 may be similar to system 100 as illustrated and described with respect to FIG. 1 . For example, a light source 10 may be configured to emit light 12 toward an optical component 110 .

In an exemplary embodiment, light 12 may interact with an aperture mask 160 . In this case, light portions 12a, 12b, 12c, and 12d may travel substantially through respective openings 162a, 162b, 162c, and 162d in aperture mask 160.

Light portion 12a may interact with a reflective surface 116a that may be disposed along a planar mirror portion 118a. Reflective surface 116a may be configured at an angle _θ a relative to support 210a or another reference plane of container 112 . In this case, light portion 12a may be reflected from reflective surface 116a as reflected light 212a. Reflected light 212a may interact with photoresist material 130 along an angle (eg, 42°) relative to substrate 140 and first surface 142. In this case, the reflected light 212a may expose the photoresist material 130 using UV light to cross-link the photoresist material 130. In doing so, reflected light 212a may help form tilted structure 134a in the background during a photoresist exposure and development process.

Likewise, light portions 12b and 12c may interact with reflective surfaces 116b and 116c, respectively. For example, light portion 12b may interact with reflective surface 116b that may be disposed along a planar mirror portion 118b. In this case, the reflective surface 116b may be configured at an angle θ _b relative to the support 210b or another reference plane or surface of the container 112 . In an exemplary embodiment, light portion 12b may be reflected from reflective surface 116b as reflected light 212b. Reflected light 212b may interact with photoresist material 130 along an angle (eg, 45°) relative to substrate 140 and first surface 142. In an example, the reflected light 212b may expose the photoresist material 130 using UV light, thereby cross-linking it. Thus, the reflected light 212b may form the tilted structure 134b at least partially in the background of a photoresist exposure and development process.

Additionally or alternatively, light portion 12c may interact with reflective surface 116c that may be disposed along a planar mirror portion 118c. In this case, the reflective surface 116c may be configured at an angle θ _c relative to the support 210c or another reference plane or surface of the container 112 . In an exemplary embodiment, light portion 12c may be reflected from reflective surface 116c as reflected light 212c. Reflected light 212c may interact with photoresist material 130 along an angle (eg, 48°) relative to substrate 140 and first surface 142. In an example, reflected light 212c may expose photoresist material 130, thereby cross-linking it. In this manner, reflected light 212c may at least partially assist in forming tilted structure 134c during a photoresist exposure and development process.

In some embodiments, light portion 12d may travel through aperture plate 160 via opening 162d. In such cases, light portion 12d may travel directly (eg, vertically or straight) toward photoresist material 130 and substrate 140. In an example, light portion 12d may expose the photoresist along a vertical (eg, normal) angle relative to substrate 140 . In such cases, light portion 12d may assist in forming vertical structures 132 in photoresist material 130 after a photoresist development process.

Although not shown, the optical component 110 may also include structures and/or devices for removing stray light. The structure may be a dark baffle disposed in the optical assembly 110 to remove stray light (eg, light reflected back into the optical assembly 110).

In some examples, an exterior of container 112 may include plumbing fittings for filling container 112 and draining light coupling material 114 from container 112 . In another exemplary embodiment, container 112 may include fittings for components (eg, optical filters, vacuum devices, etc.) to remove air bubbles or other types of gas bubbles or impurities. Additionally, in some embodiments, at least a portion of each of the reflective surfaces (eg, reflective surfaces 116a, 116b, and/or 116c) may be obscured in order to improve the directionality of light reflected from the reflective surfaces.

In other embodiments, system 200 may also include mechanical and/or optical features for aligning substrate 140 to optical component 110 and/or light source 10 . In one example, system 200 may include a stage, fixtures, optical devices (eg, magnification devices), and/or image capture devices (eg, cameras) that may be used to align substrate 140 . In one embodiment, system 200 may include a linear stage that may be used to bring substrate 140 into contact with an exit surface (eg, bottom surface 214 ), with an optical coupling material filling the space between the exit surface and substrate 140 A gap. Additionally, the exit surface may include fiducial points that may be used to align substrate 140 . For example, in-plane and rotational alignment can be achieved by aligning fiducial marks on the exit surface with features on reticle 170 . In one embodiment, two pairs of features may be viewed simultaneously using one or more cameras configured to image fiducial marks on reticle 170 relative to fiducial marks on container 112 .

Figure 2B illustrates a top view of the aperture mask 160 of the system 200 of Figure 2A, according to an exemplary embodiment. Aperture mask 160 may include opaque features and transparent features that allow light to travel through. For example, aperture mask 160 may include a plurality of openings 162 . For example, openings 162 may include a plurality of long, narrow transparent (or light-transmitting) openings 162a, 162b, 162c, and 162d in aperture mask 160.

In some cases, it may be desirable to overlap normal and oblique illumination fields at photoresist material 130 while maintaining one of substantially uniform illumination intensity in the overlapping transition regions. In such cases, the photoresist material 130 can be illuminated such that the intensity of one field increases along one direction and the intensity of adjacent fields decreases along that direction. In this manner, as illustrated in inset 216, some or all edge features of aperture mask 160 may include one or more gradient neutral density filters. In some embodiments, these filters can be configured to blur to a gradient intensity pattern at photoresist material 130 .

For example, an optical gradient intensity filter may be implemented with an opaque fine sawtooth pattern 218 along the edge of the aperture mask opening 162. Additionally or alternatively, an optical gradient intensity filter may be provided by modulating the size and/or intensity of opaque circles (eg, stipples or "dots") along an edge feature of aperture mask 160. Embodiments may utilize these sawtooth and/or dot patterns mechanically as part of the edge of aperture mask 160 or as part of a separate mask aligned to aperture mask 160 or fiducial marks on substrate 140 . Although Figure 2B depicts all sides of opening 162d as having a zigzag pattern, other designs are possible. For example, in some embodiments, only one long side of the opening may have a zigzag pattern. In such cases, the other sides of the opening may be straight (eg, not patterned).

Figure 2C illustrates various reflective surface types 220, 230, and 240 according to an exemplary embodiment. Reflective surface type 220 may include a plurality of reflective surfaces 116a, 116b, and 116c. In this case, the reflective surface may include a first mirror portion 118a, a second mirror portion 118b, and a third mirror portion 118c. Each plane mirror portion can be physically separated from each other.

Reflective surfaces 116a, 116b, and 116c may be mounted to the container via one or more supports 210a, 210b, and 210c. Support members 210a, 210b, and 210c may be fixed to maintain the orientation of reflective surfaces 116a, 116b, and 116c at a predetermined angle or orientation. Additionally or alternatively, supports 210a, 210b, and 210c may be adjustable to adjust the orientation of reflective surfaces 116a, 116b, and 116c. For example, one or all of supports 210a, 210b, and 210c may be configured to be adjustable by a piezoelectric actuator, a stepper motor, or another type of angle adjustment device. It should be understood that there are many other ways of adjusting the orientation of reflective surfaces 116a, 116b, and 116c, all of which are contemplated and possible in the context of this disclosure.

Reflective surface type 230 may include a first planar mirror portion 118a, a second planar mirror portion 118b, and a third planar mirror portion 118c (which may be physically coupled together by a continuous mirror surface or another type of coupling structure). A continuous lens. In other words, in some embodiments, the mirror portions may be coupled to each other and attached to container 112 via supports 232 . In this case, the mirror sections do not need to be individually supported or mounted. Alternatively, a single continuous mirror may be physically supported by a single support member (eg, support member 232).

Reflective surface type 240 may include a curved mirror portion 119 having a corresponding curved reflective surface 116d. The curved mirror portion 119 may be curved in an axially symmetric manner (eg, have a cylindrical curvature). However, in other embodiments, curved mirror portion 119 may be curved according to another shape.

Figure 2D illustrates a photoresist structure 250 according to an exemplary embodiment. Figure 2D illustrates photoresist structure 250 after development of photoresist material 130. In particular, after exposure of sloped structures 134a, 134b, 134c, and 132, various portions of photoresist material 130 may be removed to reveal the surface of photoresist structure 250. In some embodiments, sloped structures 134a, 134b, and 134c may have different mirror angles relative to first surface 142 of structure 140. Although FIG. 2D depicts photoresist structure 250 as having one specific shape, other shapes are possible and contemplated herein.

Figure 2E illustrates an optical assembly 110 according to an exemplary embodiment. FIG. 2E is a perspective view of the light input side of the optical component 110 . Optical assembly 110 may include a container 112 . Optical component 110 may include a first reflective surface 116 and a second reflective surface 270. Optical assembly 110 may also include a transparent top window 260 and a transparent bottom window 262.

Figure 2F illustrates an optical assembly 110 according to an exemplary embodiment. FIG. 2F is a perspective view of the light output side of the optical component 110 . Optical assembly 110 may include a container 112 . As shown in Figure 2F, the optical component 110 may also include a first reflective surface 116, a transparent top window 260, and a transparent bottom window 262.

Figure 3A illustrates a system 300 according to an exemplary embodiment. System 300 may be similar or identical to system 100 and/or system 200 as illustrated and described with respect to Figures 1 and 2A. For example, system 300 may include a light source 10 and a container 112 at least partially filled with light coupling material 114 . System 300 may also include a first reflective surface 116 and a second reflective surface 270.

In an exemplary embodiment, system 300 includes an aperture mask 160 disposed between an exit surface (eg, bottom surface 214 ) of container 112 and photoresist material 130 . In this case, the light emitted from the light source 10 may be reflected from the first reflective surface 116 and the second reflective surface 270 and illuminate the aperture mask 160 . A portion of the reflected light may be transmitted through openings 162 in aperture mask 160.

Light transmitted through aperture mask 160 may expose photoresist material 130 , which may cover first surface 142 of substrate 140 . As described herein, the angle of transmitted light can be controlled or manipulated to expose tilted structures in photoresist material 130.

Figure 3B illustrates a system 320 according to an exemplary embodiment. System 320 may be similar or identical to system 100 and/or system 200 as illustrated and described with respect to Figures 1 and 2A. For example, system 320 may include a light source 10 and a container 112 at least partially filled with light coupling material 114 . System 320 may also include a first reflective surface 116 and a second reflective surface 270.

In some embodiments, system 320 may include light source 10 disposed below (eg, below) container 112 . Thus, light emitted from light source 10 may be directed upward toward a bottom surface 214 of container 112 .

In these cases, system 320 includes an aperture mask 160 disposed within container 112 along a bottom interior surface of the container. In this case, light emitted from light source 10 may be incident on aperture mask 160 and transmitted through opening 162 toward reflective surfaces 116 and/or 270 . A portion of the transmitted light may be reflected by reflective surfaces 116 and/or 270 to expose photoresist material 130 that may cover a first surface 142 of a substrate 140 .

Figure 3C illustrates a system 330 according to an exemplary embodiment. For example, system 330 may be similar or identical to system 100 and/or system 200 as illustrated and described with respect to FIGS. 1 and 2A. For example, system 330 may include a light source 10 and a container 112 at least partially filled with light coupling material 114 . System 330 may also include a first reflective surface 116 and a second reflective surface 270.

In some embodiments, system 330 may include light source 10 disposed below (eg, below) container 112 . Thus, light emitted from light source 10 may be directed upward toward a bottom surface 214 of container 112 .

In such cases, system 330 includes an aperture mask 160 that may be disposed within container 112 and adjacent to photoresist material 130 . For example, the aperture mask may be in soft or hard contact with the photoresist material 130 . In this case, light emitted from light source 10 may be incident on reflective surfaces 116 and/or 270 . The reflected light and transmitted light will be incident on the aperture mask 160 and transmitted through the opening 162 toward the photoresist material 130 to expose the photoresist material 130 that may cover a first surface 142 of a substrate 140 . III. Exemplary optical system

4A and 4B illustrate an optical system 400 and portions thereof according to an exemplary embodiment. Optical system 400 may be a compact LIDAR system incorporating optical light guide elements. Such a LIDAR system can be configured to provide information (eg, point cloud data) about one or more objects (eg, location, shape, etc.) in a given environment. In an exemplary embodiment, the LIDAR system may provide point cloud information, object information, mapping information, or other information to a vehicle. The vehicle can be semi-automatic or fully automatic. For example, the vehicle may be an autonomous car, an autonomous drone, an autonomous truck, or an autonomous robot. Other types of vehicles and LIDAR systems are considered in this article.

Figure 4A illustrates a schematic block diagram of an optical system 400 according to an exemplary embodiment. Optical system 400 includes a substrate 410, a light emitter device 420, and an optical waveguide 430. In some embodiments, light emitter device 420 may include a laser assembly that includes one or more laser bars. Additionally or alternatively, optical system 400 may include a cylindrical lens 422. In some examples, cylindrical lens 422 may include an optical fiber.

The optical waveguide 430 is arranged along one surface of the substrate 410 . Optical waveguide 430 includes at least one mirror surface 432. Optical waveguide 430 is configured to guide light emitted by light emitter device 420. This light may be guided within at least a portion of optical waveguide 430 via total internal reflection.

In some embodiments, at least one mirror surface 432 of optical waveguide 430 may include a reflective material, such as a metallic coating. In some embodiments, the metal coating may include one or more metals, such as titanium, platinum, gold, silver, aluminum, and/or another type of metal. In other embodiments, at least one mirror surface 432 may include a dielectric coating and/or a dielectric stack.

In such cases, a portion of the directed light interacts with mirror surface 432 to direct the reflected light into an environment of optical system 400 . In some embodiments, mirror surface 432 may be configured at at least one of 42 degrees, 45 degrees, or 48 degrees relative to substrate 410 .

Light emitter device 420 may be configured to emit light toward a cylindrical lens 422 , which may help focus, defocus, direct, and/or otherwise couple the emitted light into optical waveguide 430 .

Optical system 400 is one of a variety of different optical systems that may include a light guide, such as optical waveguide 430 formed from a photoresist material 130 or other optical material. In an exemplary embodiment, optical waveguide 430 may be coupled to a transparent substrate. In such cases, mirror surface(s) 432 may be configured to direct light emitted by light emitter device 420 toward the transparent substrate and subsequently into the environment of optical system 400 .

Figure 4B illustrates a top view and a side view of an optical system 400 according to an exemplary embodiment. As shown in Figure 4B, optical waveguide 430 may be similar or identical to photoresist system 250 as shown and described with respect to Figure 2D.

As an example, optical waveguide 430 may include three mirror surfaces 432a, 432b, and 432c. Mirror surfaces 432a, 432b, and 432c can have different angles. For example, mirror surface 432a may be oriented at a 42° mirror angle relative to the surface of substrate 410. Additionally or alternatively, mirror surface 432b may be oriented at a 45° mirror angle relative to the surface of substrate 410. Still further, mirror surface 432c may be oriented at a 48° mirror angle relative to the surface of substrate 410. It should be understood that other mirror angles (eg, between 30° and 60°) are possible and considered. Additionally, it should be understood that while FIG. 4B depicts one specific configuration of mirror surface 432, it should be understood that other configurations of mirror surface 432 and other elements of optical waveguide 430 are possible and contemplated.

In some embodiments, optical system 400 may include a light emitter device 420 and a cylindrical lens 422. Cylindrical lens 422 may be disposed between light emitter device 420 and one input surface 450 of optical waveguide 430. Light emitter device 420 may be configured to emit emitted light 421 toward cylindrical lens 422 .

For example, as shown in Figure 4B, light emitter device 420 can emit emitted light 421, which can be coupled into optical waveguide 430 via input surface 450. In this case, light portions 424a, 424b, and 424c may be reflected toward an environment via mirror surfaces 432a, 432b, and 432c, respectively. Reflected light portions 440a, 440b, and 440c may be coupled out through substrate 410 (which may be substantially transparent). Reflective light portions 440a, 440b, and 440c may interact with objects in the environment (eg, via reflection, absorption, and/or refraction).

In other words, after interacting with cylindrical lens 422, various portions of emitted light 421 may be coupled into optical waveguide 430. For example, a first light portion 424a may interact with mirror surface 432a. In this case, the first light portion 424a may be reflected from the mirror surface 432a, thereby forming the first reflected light 440a. Additionally, a second light portion 424b can interact with mirror surface 432b. In this case, the second light portion 424b may be reflected from the mirror surface 432b, thereby forming the second reflected light 440b. Additionally, a third light portion 424c can interact with mirror surface 432c. In this case, the third light portion 424c may be reflected from the mirror surface 432c, thereby forming the second reflected light 440c.

As shown, the first reflected light 440a, the second reflected light 440b and the third reflected light 440c may be reflected at different angles relative to the surface of the substrate 410. For example, the first reflected light 440a, the second reflected light 440b, and the third reflected light 440c may be within ±6° relative to the surface normal of the substrate 410. Other reflection angles are possible and considered. IV. Illustrative Methods

Figure 5 illustrates a method 500 according to an exemplary embodiment. It should be understood that method 500 may include fewer or more steps or blocks than those explicitly illustrated or otherwise disclosed herein. Furthermore, the respective steps or blocks of method 500 may be performed in any order and each step or block may be performed one or more times. In some embodiments, some or all of the blocks or steps of method 500 may be associated with elements of system 100 and/or optical system 400 as illustrated and described with respect to Figures 1, 4A, and 4D.

Block 502 includes placing a substrate near one end of an optical component, wherein the photoresist material covers at least a portion of a first surface of the substrate, and wherein the optical component includes: (i) a container holding an optical coupling material ; and (ii) a reflective surface.

Block 504 includes causing a light source to emit light into an optical component, wherein the reflective surface reflects at least a first portion of the emitted light to illuminate the photoresist material at one or more desired angles, thereby causing one of the photoresist materials to At least a portion of the tilted structure is exposed.

In some embodiments, the one or more desired angles may include orienting the one or more reflective surfaces at at least one of: 42 degrees, 45 degrees, and 48 degrees relative to the first surface. It is to be understood that other desired angles are contemplated and possible within the scope of the invention.

In some examples, methods may include overlaying an aperture mask on or near one of the surfaces of the optical component. The aperture mask may include one or more openings, each opening corresponding to a respective desired structure in the photoresist material. At least a portion of the emitted light transmitted through each opening exposes the respective desired structure to which the opening corresponds.

In some embodiments, the aperture mask includes a first opening. In these cases, the first opening is configured to allow a first portion of the emitted light to interact with a first portion of the reflective surface. The first portion of the reflective surface is configured to redirect the first portion of emitted light to expose at least one tilted structure.

In one embodiment, method 500 may involve determining desired structures to be fabricated, such as vertical structures and/or tilted structures. Additionally, method 500 may involve determining parameters of the desired structure. Additionally, method 500 may involve determining the dimensions of a desired structure. Additionally, method 500 may involve determining a desired tilt angle for a desired tilted structure. For example, the desired tilt angle may be between 30 degrees and 60 degrees relative to a substrate surface.

As explained above, the desired tilt angle of the tilted structure determines the mirror orientation angle. Thus, method 500 may also involve determining mirror orientation angles θ _a , θ _b (which may be determined using Snell's law). Snell's law states that the ratio of the angle of incidence to the sine of the angle of refraction is equal to the reciprocal of the ratio of the refractive index, which is expressed by the following formula:

The desired refraction angle (θ ₂ ) in the photoresist material (e.g., photoresist material 130), the refractive index (n 1 ) of the optical coupling material (e.g., optical coupling material 114), and the refractive index (n ₁ ) of the photoresist material ( n ₂ ) is known and can be used to calculate a desired angle of incidence. For example, the incident angle may be within an angle range between 15 degrees and 45 degrees (inclusive) from normal incidence. It should be understood that other angles are possible and that dynamically varying angles of incidence are also possible.

Based on the angle of incidence, the mirror orientation angles (eg, angles θ _a , θ _b and/or θ _c as illustrated and described with respect to FIG. 2A ) may be calculated. In particular, the angle can be calculated so that light reflected from the reflective surface(s) is incident on the photoresist material at a desired angle of incidence. Once the angle is calculated, method 500 may also involve adjusting the adjustable coupling components (eg, supports 210a, 210b, and/or 210c) so that the reflective surface is positioned at the desired angle.

Method 500 may also involve providing a wafer including a substrate (eg, substrate 140 ) overlaid with photoresist material. In such cases, providing the substrate may involve preparing the photoresist material by depositing a photoresist on the substrate 140 and then baking the photoresist material. Additionally, providing the wafer may include disposing a photoresist material on the wafer. Additionally, providing the wafer may involve aligning the wafer with optical components. As explained herein, aligning the wafer may involve aligning fiducials on an exit surface (eg, bottom surface 214) with features on a reticle (eg, reticle 170).

Method 500 may also involve causing a light source to emit light directed toward an optical component. For example, the light source may emit light toward the optical component by emitting light with a substantially uniform illumination intensity across a first surface of the optical component. In exemplary systems in which the light source is not positioned above the optical component, light from the light source may be redirected toward the optical component via one or more optical elements (eg, mirrors, light guides, etc.).

The specific configurations shown in the figures should not be considered limiting. It is understood that other embodiments may contain more or less of the elements shown in a given figure. Additionally, some of the illustrated elements may be combined or omitted. Still further, an illustrative embodiment may include elements not shown.

A step or block representing a processing of information may correspond to circuitry that can be configured to perform the specific logical functions of a method or technique described herein. Alternatively or additionally, a step or block representing a process of information may correspond to a module, a fragment, or a portion of program code (including associated data). The program code may include one or more instructions executable by a processor for implementing specific logical functions or actions in a method or technique. The program code and/or related data may be stored on any type of computer-readable medium (such as a storage device including a disk, hard drive, or other storage medium).

Computer-readable media may also include non-transitory computer-readable media, such as computer-readable media that stores data for short periods of time, such as register memory, processor cache, and random access memory (RAM). Computer-readable media may also include non-transitory computer-readable media that stores code and/or data for an extended period of time. Thus, computer-readable media may include secondary or permanent long-term storage, such as, for example, read-only memory (ROM), optical or magnetic disks, and compact disc-read-only memory (CD-ROM). Computer-readable media can also be any other volatile or non-volatile storage system. A computer-readable medium may be considered, for example, as a computer-readable storage medium or a tangible storage device.

Although various examples and embodiments have been disclosed, others will be apparent to those skilled in the art. The various disclosed examples and embodiments are for illustrative purposes and are not intended to be limiting, with the true scope being indicated by the following patent claims.

10: light source 12: light 12a: light part 12b: light part 12c: light part 12d: light part 14: at least a first part of the light 16: a second part of the emitted light 100: system 110: optical component 112: container 114: Optical coupling material 116: Reflective surface 116a: Reflective surface 116b: Reflective surface 116c: Reflective surface 116d: Curved reflective surface 118: Plane mirror part 118a: First plane mirror part 118b: Second plane mirror part 118c: Third plane mirror part 119: Curved mirror part 130: photoresist material 132: vertical structure 134: tilted structure 134a: tilted structure 134b: tilted structure 134c: tilted structure 140: substrate 142: first surface 160: aperture mask/aperture plate 162: opening 162a: Opening 162b: Opening 162c: Opening 162d: Opening 170: Photomask 200: System 210a: Support 210b: Support 210c: Support 212a: Reflected light 212b: Reflected light 212c: Reflected light 214: Bottom surface 216: Illustration 218: Opaque fine serrated pattern 220: Reflective surface type 230: Reflective surface type 232: Support 240: Reflective surface type 250: Photoresist structure 260: Transparent top window 262: Transparent bottom window 270: Second reflective surface 300: System 320: System 330: System 400: Optical system 410: Substrate 420: Light emitter device 421: Emitted light 422: Cylindrical lens 424a: Light part/First light part 424b: Light part/Second light part 424c: Light part/ Third light part 430: Optical waveguide 432: Mirror surface 432a: Mirror surface 432b: Mirror surface 432c: Mirror surface 440a: Reflected light part/First reflected light 440b: Reflected light part/Second reflected light 440c: Reflected light part/ Third reflected light 450: input surface 500: method 502: block 504: block θ _a : angle θ _b : angle θ _c : angle

Figure 1 illustrates a system according to an exemplary embodiment.

Figure 2A illustrates a system according to an exemplary embodiment.

Figure 2B illustrates an aperture mask of the system of Figure 2A, according to an exemplary embodiment.

Figure 2C illustrates various reflective surface types according to an exemplary embodiment.

Figure 2D illustrates a photoresist structure according to an exemplary embodiment.

Figure 2E illustrates an optical assembly according to an exemplary embodiment.

Figure 2F illustrates an optical assembly according to an exemplary embodiment.

Figure 3A illustrates a system according to an exemplary embodiment.

Figure 3B illustrates a system according to an exemplary embodiment.

Figure 3C illustrates a system according to an exemplary embodiment.

Figure 4A illustrates an optical system according to an exemplary embodiment.

Figure 4B illustrates an optical system according to an exemplary embodiment.

Figure 5 illustrates a method according to an exemplary embodiment.

10:Light source

12:Light

14:Light at least one part one

16: Emitted Light Part 1

100:System

110:Optical components

112: Container

114: Optical coupling materials

116: Reflective surface

118: Plane mirror part

119: Curved mirror part

130: Photoresist material

132:Vertical structure

134: Inclined structure

140:Substrate

142: First surface

160:Aperture Mask/Aperture Plate

162:Open your mouth

170: Photomask

Claims (16)

An optical system comprising: an optical assembly configured to direct light emitted by a light source to illuminate a photoresist material at a plurality of different angles so as to cause a plurality of different tilted structures in the photoresist material (angled structure) simultaneously exposed, wherein the photoresist material covers at least a portion of a first surface of a substrate, and wherein the optical assembly includes: a container that contains one of the plurality of different angle selections based at least in part on Optical coupling material; a reflective surface configured to reflect at least a first portion of the emitted light to illuminate the photoresist material at the plurality of different angles, wherein the reflective surface includes a plurality of corresponding to the plurality of different angles a plane mirror portion; and an aperture mask positioned between the light source and the substrate, wherein the aperture mask includes one or more openings, each opening corresponding to a respective desired structure in the photoresist material, and Wherein at least a portion of the emitted light transmitted through each opening exposes the respective desired structure corresponding to the opening. The system of claim 1, wherein the plurality of different angles include: 42 degrees, 45 degrees and 48 degrees relative to the first surface. The system of claim 1, wherein the plurality of different angles include a plurality of angles relative to the first surface selected from an angle range between 30 degrees and 60 degrees. The system of claim 1, wherein the reflective surface includes one or more curved mirror portions. The system of claim 1, wherein the respective desired structures include at least one vertical structure and at least one inclined structure. The system of claim 5, wherein the aperture mask includes a first opening, wherein the first opening is configured to allow the first portion of the emitted light to interact with a first portion of the reflective surface, and wherein the The first portion of the reflective surface is configured to redirect the first portion of the emitted light to expose the at least one tilted structure. The system of claim 5, wherein the aperture mask includes a second opening, and wherein the second opening is configured to allow a second portion of the emitted light to expose the at least one vertical structure. The system of claim 1, wherein at least a portion of a first surface of the container and at least a portion of a second surface of the container are transparent, and wherein the emitted light enters the container through the transparent portion of the first surface , and wherein the emitted light illuminates the photoresist material through the transparent portion of the second surface. The system of claim 1, further comprising a photomask disposed proximate the photoresist material, wherein the photomask is configured to define individual desired structures in the photoresist material. The system of claim 1, wherein the optical assembly further includes a device configured to remove stray light within the optical assembly. The system of claim 1, wherein the light source includes an anisotropic collimated light source. The system of claim 1, wherein the optical coupling material includes at least one of the following: water, ethylene glycol, and glycerin. The system of claim 1, wherein the substrate is soaked in the optical coupling material such that the photoresist material faces a surface of the container, wherein at least a portion of the surface of the container is transparent, and wherein the light from the light source The emitted light enters the container through the transparent portion of the surface of the container. A method of manufacturing an optical device comprising: placing a substrate near one end of an optical assembly, wherein a photoresist material covers at least a portion of a first surface of the substrate, and wherein the optical assembly includes: (i) a container containing an optical coupling material; and (ii) a reflective surface; causing a light source to emit light into the optical assembly, wherein the reflective surface reflects at least a first portion of the emitted light in accordance with Illuminating the photoresist material at a plurality of different angles, thereby simultaneously exposing at least a portion of a plurality of different tilted structures in the photoresist material, wherein the reflective surface includes a plurality of plane mirror portions corresponding to the plurality of different angles; and overlaying an aperture mask on or near a surface of the optical assembly, wherein the aperture mask includes one or more openings, each opening corresponding to a respective desired structure in the photoresist material, and wherein the aperture mask is At least a portion of the emitted light transmitted through each opening exposes the respective desired structure corresponding to the opening. The method of claim 14, wherein the plurality of different angles include: 42 degrees, 45 degrees and 48 degrees relative to the first surface. The method of claim 14, wherein the respective desired structures include at least one vertical structure and at least one tilted structure, wherein the aperture mask includes a first opening, wherein the first opening is configured to allow the emitted light to The first portion interacts with a first portion of the reflective surface, and wherein the first portion of the reflective surface is configured to redirect the first portion of the emitted light to expose the at least one tilted structure.